JPS5938877A - Paper leaf discriminating method - Google Patents

Abstract

PURPOSE:To cause no malfunction even if sensitivity of a detector is varied gradually, by updating a comparing and discriminating value at all times whenever paper money passes through. CONSTITUTION:An output of a photodetecting part 1 of a detector is inputted to an A/D converter 3 and a tip detecting circuit 4 through an amplifier 2, and their outputs are inputted to an operation control device and a program memory part (CPU) 5. The CPU 5 discriminates a paper leaf in accordance with data from a pattern memory 8, a reference value memory 9 and a discriminating value memory 10. The data of the discriminating value memory 10 is updated at all times whenever paper money passes through, and the CPU 5 discriminates the paper money by this updated by money comparing and discriminating value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper sheet discrimination method, and more particularly to a paper sheet discrimination method for determining banknote abnormalities and banknote conveyance abnormalities in a plurality of banknotes of the same type.

For example, in a banknote counting device that counts multiple banknotes of the same type, the banknotes are counted by passing seven banknotes at a time in front of a detector. It simultaneously detects dirt on the banknotes, shape of banknotes, reversed front and back, etc.), and abnormalities in banknote conveyance (for example, posture of banknotes, multi-feeding of banknotes overlapping each other, chains of banknotes being fed together, etc.). If an abnormality is detected, the banknote counting operation is stopped. As a method for detecting such an abnormality, for example, a standard banknote printing pattern selected in advance for each banknote denomination is set and stored in a storage unit as a set value, and the
``There is a system in which the printing pattern signal of the banknote is compared with the printing pattern setting value signal from the storage section. For example, in a translucent type detector, light from a light emitting source is applied to the passing banknote, and the light transmitted through the banknote is received by a light detection section, thereby deriving a pattern signal of the banknote.

However, when determining abnormalities in banknotes in this way, paper dust 1 dust attached to the banknote.

The detection sensitivity of the detector gradually changes due to printing ink etc. adhering to the detector or a decrease in the luminous intensity of the light emitting source over time. There is a drawback that the difference between the printed pattern detected by the method gradually increases and a normal banknote is mistakenly judged as an abnormal banknote.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a paper leaf discrimination method that is not affected by changes in the detector over time.

In order to achieve this object, according to the present invention, a plurality of paper sheets of the same type are successively passed in front of at least seven light detection sections, and a print pattern signal of each of the paper sheets passing through is detected by the light detection section. In the leaf discrimination method, a pulse is generated while each paper leaf passes in front of the light detection part, The step of determining the length of each sheet by counting the number of pulses, and the step of determining the length of each sheet by counting the number of pulses; While erasing from the pattern memory, the first print pattern signal of the first sheet passing through the light detection section this time is erased from the pattern memory.
a step of storing the signal in the pattern memory in correspondence with the pulse; and calculating a first comparison discrimination value based on the first print pattern signal at a predetermined portion within the length of the sheet; The step of storing the comparative discriminant value of
and the first comparative discriminant value stored in the discriminant value memory, and when the result of the mutual comparison is determined to be normal, the current , a step of self-judging the first print pattern signal stored in the pattern memory, and when the self-judgment result is determined to be normal, the first comparison discrimination stored in the reference value memory; There is provided a paper sheet discrimination method including the step of deleting the value and transferring the first comparative discriminant value stored in the discriminant value memory to the reference value memory.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing the circuit configuration for carrying out the method of the present invention. In the figure, the output side of the photodetecting section of the detector is connected to an amplifier, The sensor is connected to an analog/digital (A/D) converter 3 and tip detection circuitry. The output side of the A/D converter 3 and the tip detection circuit is an arithmetic/control unit and a program memory unit (hereinafter referred to as 0PU)! Further, the pulse output from the encoder 6 is given to a pulse control circuit, and the output side of the pulse control circuit is connected to the aforementioned CPU j.

Furthermore, a pattern memory, a reference value memory 7, and a discrimination value memory 10 are connected to the CPU &, and an output terminal /l for outputting an abnormality signal when an abnormality occurs is also connected.

Next, the operation shown in FIG. 1 will be explained using FIGS. 2 to 7. When the leading edge of the banknote reaches the light detection unit /, a signal is sent from the light detection unit l to the leading edge detection circuit DA via the amplifier KO, and the circuit DA sends a signal to the CPU k and the pulse control circuit 7 when the leading edge of the banknote has passed. send a signal to let you know. The pulse control circuit 7 that receives this leading edge passage signal applies a pulse from the encoder 6 that constantly generates a pulse to 0PUI, and while the banknote passes the detector, the pulse is synchronized with the progress of the banknote. (pulse signal sb in Figure 1).
The CPU that received the signal from the tip detection circuit! r is A
A start signal is sent to the /D converter 3, and the printing pattern signal (signal 8a in FIG. 2) of the banknote passing through the photodetector / is detected.
It is input from the output side of the A/D converter 3 in synchronization with the encoder pulse sb sent from the pulse control circuit 7 (signal Sc in FIG. 2).

Signals 8a and Sc shown in FIG.
It is also shown in FIG. 1 as the banknote printing pattern signal at the input side of the D converter 3 and the banknote printing pattern signal provided from the converter 3 to the CPU j. L in Figure 1 represents the total number of encoder pulses, that is, the length of the banknote. During this length L, the CPU and t collect the print pattern signal Sc of the paper (7) banknote in synchronization with the pulses. ing.

A method for determining abnormalities in one banknote and transport abnormality based on banknote printing pattern data Sc from the A/D converter 3 input to the CPU j- is shown in FIGS. 3(al, (1)) and (1).
The case of three consecutive passing banknotes shown in C1 will be explained as an example.

FIG. 3 (al, (t)) and (0) show the OPU from the A/D converter 3 when the first, second and third banknotes successively pass in front of the photodetector l. The signals S7, S2 and S applied to & are shown. At first, when the first banknote passes, the pattern memory t is as shown in Fig. 3(a).
The print pattern signal SL+ is temporarily stored in an erasable manner. Next, 0PUj is the average value VS of the length and portion of the banknote in the print pattern signal S11, and a predetermined range value ■ based on the average value, according to the calculation program.

~V, is calculated as a comparative discriminant value. Length of banknote Ll
is specified by calculating the range of Pn, ~Pn! by calculating the number of pulses from s"1 to Pn as shown in FIG. 2. Even if the first banknote is the first banknote to pass, For example, a comparison discrimination value consisting of these average value VS and range value ■.~■ is first stored in a reference value memory zo.Then, the print pattern data in the pattern memory t is stored using the comparison discrimination value stored in this reference value memory zo. SZ, and performs so-called self-discrimination of the first banknote currently passing.

If the banknote is normal, when the next first banknote passes, the print pattern signal 81 stored in the pattern memo IJg
m is erased, and the printing pattern signal Sh of the first banknote is stored in the memory t. Same as last time, print pattern signal 8
1. Based on the length of the banknote, in parts, Figure 3 +1
)), the average value VS, and the range value V! ~V is calculated as a comparative discriminant value, and this comparative discriminant value is then stored in the discriminant value memory 10.

Next, the comparison discriminant value stored in this discriminant value memory 10,
A mutual comparison is made with the previous comparison judgment value stored in the reference value memory.

This mutual comparison is performed as follows. First, Figure 9 (
As shown in a), the range value V, ~
Compare V and the previous average value VS of the first banknote, and the average value VS is the range value ■! If it is within ~v3, the previous first banknote is considered to be the same type of banknote as the current first banknote, and then the range value v0~ according to the previous first banknote is determined as shown in Fig. V,
and the average value VS based on the first banknote this time.

The average value VS is the range value ■. ~■, then the current comparative discrimination value (average value VS and range value vt~■s) of the first banknote is considered normal.

Next, the comparison discrimination value of the current first banknote stored in the discrimination mesori/θ that is considered normal, and the current printing pattern signal SZ stored in the pattern memory,
(FIG. 3(b)), self-determination similar to the previous time is performed, and abnormality of the first banknote itself is determined.

If both the above-mentioned mutual comparison and self-discrimination are within the normal range, the first and first banknotes are determined to be the same banknote or normal banknote. The previous comparison judgment value stored in the reference value memory is then erased.
Is the current comparison discriminant value stored in discriminant value memo IJ/0 the reference value memory? will be moved to

Next, when the third bill passes through the light detection section/, the CPU &
Similarly, the average value VS3 and the range value 4 to V shown in FIG. Figure 9 (C
) and T(1), mutual comparison is performed, and then self-judgment is performed. If normal, the previous comparison discrimination value stored in the reference value memory 9 is erased, and this time The comparison discrimination value of this third bill is transferred to the reference value memory 9 as a comparison discrimination value for the next bill to pass, and the bill passes through the detector with the updated comparison discrimination value. distinguishing between banknotes and banknotes.

FIG. 5 shows a case where a part of the print pattern signal SLn is outside the predetermined range of values ■n-2 to vn-1 when the above-mentioned self-judgment is performed. In this case, the CPU h determines that the banknote is defective, and an abnormal signal is output from the output terminal l/ shown in FIG.

Also, Fig. 6 shows a case where an abnormal signal is generated when mutual comparison is performed, and the previous average value vBn1 is the current range value v
■~V is outside the old range (Figure 6 (a)), and the current average value is V8n! is the previous range value ■n.

.about.vnI (FIG. 6(b)). If at least seven states shown in FIGS. 6(a) and 6(b) occur, an abnormality signal is similarly output from the output terminal //.

FIG. 7 shows changes in the range and average value of the comparative discrimination value when the first to third three banknotes pass.

The above comparison discrimination value and the number of pulses from the encoder P1
~ By using the value of Pn, it is possible to identify abnormalities in banknotes, such as the mixing of different types of banknotes, soiling of banknotes, shape of banknotes, reversed front and back sides, etc., as well as the orientation of 5 banknotes and the fact that they are being sent in piles. It is also possible to determine abnormalities in the conveyance of banknotes, such as double feeding or chains of banknotes being fed together.

As described above, according to the present invention, the comparison discrimination value is always updated every time a banknote passes, and the updated comparison discrimination value is used to sequentially discriminate the banknotes passing through the detector. Therefore, even if the sensitivity of the detector gradually changes, it will not malfunction due to its influence.

[Brief explanation of the drawing]

FIG. 7 is a block circuit diagram for explaining an embodiment of the present invention, and FIGS. 2 to 7 are waveform diagrams for explaining a paper sheet discrimination method according to an embodiment of the present invention. In the figure, l is a photodetection section, da is a tip detection circuit, a dodging calculation/control device and a program memory section, 6 is an encoder for pulse generation, g is a pattern memory, 9 is a reference value memory, 10 is a discrimination value memory, l/ is a terminal for outputting an abnormal signal, L is the length of the paper sheet, L is a predetermined portion within the length of the paper sheet, S1181° and 81. are the first, second, and third print pattern signals, VS, VS, and VS are the predetermined portions between the first, second, and third Pn□ to Pn2, respectively, and the comparative discriminant values at Average value, ■. ~■1,
(2), ~V, and (4) ~V are predetermined range values of the first, second, and third comparison discrimination values, respectively. Patent applicant Musashi Engineering Co., Ltd. Figure 1 Figure 21gI Figure 6 b Bad time (1) Figure 7 Time (1)

Claims (1)

[Scope of Claims] (1) A plurality of paper sheets of the same type are successively passed in front of at least one light detection section, and a print pattern signal of each of the paper sheets passing through is extracted from the light detection section. , in a paper sheet discrimination method in which an abnormality of the paper sheet is determined based on the printing pattern signal, a pulse is generated while each paper sheet passes in front of the light detection section, and the number of pulses is counted. determining the length of each sheet by
erasing the first print pattern signal from the pattern memory, and storing the first print pattern signal of the second sheet currently passing through the photodetector in the pattern memory in correspondence with the pulse. calculating a first comparative discriminant value based on the first print pattern signal at a predetermined portion within the length of the sheet, and storing the first comparative discriminant value in a discriminant value memory; a step of mutually comparing a previous first comparison discriminant value stored in a reference value memory and the first comparison discriminant value stored in the discriminant value memory, and determining that the result of the mutual comparison is normal; and when the first print pattern signal currently stored in the pattern memory is determined to be normal based on the second comparison determination value. the step of erasing the first comparison discriminant value stored in the reference value memory and moving the first comparison discriminant value stored in the discriminant value memory to the reference value memory; Paper leaf identification method. (, 2) the comparison discriminant value is an average value of the λ-th print pattern signal in a predetermined portion within the length of the paper sheet;
2. The paper sheet discrimination method according to claim 1, further comprising: a predetermined range value of the print pattern signal calculated based on this average value. (3) The mutual comparison between the first comparative discriminant value stored in the reference value memory and the first comparative discriminant value stored in the discriminant value memory is performed in accordance with the first comparative discriminant value. confirming that the average value of the values is within a predetermined range of the first comparative discriminant value, and the average value of the second comparative discriminant value is within a predetermined range value of the first comparative discriminant value. 2. A method for determining paper sheets according to claim 1, comprising the step of confirming that the paper sheets are within the range.